Circulating MicroRNAs as Biomarkers and Mediators of Cell-Cell Communication in Cancer

Abstract

The realization of personalized medicine for cancer will rely not only on the development of new therapies, but on biomarkers that direct these therapies to the right patient. MicroRNA expression profiles in the primary tumor have been shown to differ between cancer patients and healthy individuals, suggesting they might make useful biomarkers. However, examination of microRNA expression in the primary tumor requires an invasive biopsy procedure. More recently, microRNAs have been shown to be released from the primary tumor into the circulation where they can be utilized as non-invasive biomarkers to diagnose patients, predict prognosis, or indicate therapeutic response. This review provides an overview of the current use of circulating microRNAs as biomarkers as well as recent findings on their role in regulating cell signaling interactions in the tumor microenvironment.

Keywords: cancer; circulating biomarker; micron.

Figure 1

Cell–cell communication through exosomal microRNAs. MicroRNAs contained in exosomes are released from tumor cells where they can enter the bloodstream and circulate through the body to distant sites. These exosomal microRNAs are taken up by recipient cells, where the microRNAs can then suppress target genes in recipient cells.